Revert "filename param can be a String (tests, for example)"
Revert "filename param can be a String (tests, for example)"

This reverts commit f59bb30d43bcdb14d23aebcd6c6d919975ab4f34.

CartoDB/cartodb,splashblot/dronedb,splashblot/dronedb,CartoDB/cartodb,CartoDB/cartodb,splashblot/dronedb,CartoDB/cartodb,CartoDB/cartodb,splashblot/dronedb,splashblot/dronedb